Let-off for looms



Dec. '28, 1937. v PAYNE 2,103,821

LET-OFF FOR LOOMS Filed Jan. 7, 1937 2 Sheets-Sheet 1 w Fla) Inventor Oscar \l. Payne Attorney 7 Patented Dec. 28, 1937' UNITED STATES PATENT OFFICE LET-OFF FOR LOOMS Application January 7,

Claims.

This invention relates to improvements in let-' offs for looms and it is the general object of the invention to provide a self-adjusting let-off responsive to variations in warp tensions.

The warp thread in certain types of looms V rises from the beam and extends over a whip roll from whence it extends to the harnesses. It is a further object of my invention to provide means whereby movement of the whip roll regulates the turning of the Warp beam, the force for turning the beam being derived from the warp.

It is a further object of my invention to provide a weighted let-off so constructed as to give a substantially uniform feed as the diameter of the warp beam diminishes.

It is a still further object of my invention to provide a let-off the regulating elements of which are in the form of an escapement which is controlled by the whip roll, the escapement being held against action when the whip roll is in its rearmost position and being released to permit turning of the warp beam by forward motion of the whip roll.

It is a further object of the invention to cause the whip roll to have a parallel back and forth motion by means of a cross connection effective to apply the same pressure at each end of the whip roll.

With these and other objects in view which will appear as the description proceeds, my invention resides in the combination and arrangement of parts hereinafter described and set forth in the claims.

In the accompanying drawings, wherein a convenient embodiment of my invention is set forth,

Fig. 1 is a diagrammatic plan view of the rear part of a loom having my invention applied thereto,

Fig. 2 is an enlarged end elevation looking in the direction of arrow 2, Fig. 1, the weight being omitted.

Fig. 3 is a vertical section on line 3-3 of" Fig. 2, and

Fig. 4 is a detail vertical section on line 4-4 of of Fig. 2, on an enlarged scale.

Referring to the drawings, where there is shown the rear part only of the loom, the loomsides It support rearwardly projecting brackets provided with pockets |2 to receive the gudgeons l3 of a warp beam M. The warp W is led upwardly from the beam over a whip roll 1937, Serial No. 119,515

23 rotatable about a fixed stud 24 supported by a housing I8. The gear 23 meshes with a pinion 25 rotatable about a fixed stud 26 carried by the housing and rotating with a gear 21. The latter in turn meshes with a pinion 28 secured to a shaft 29 rotatable in a bearing IQ of the housing I8 bolted to the adjacent bracket The matter thus far described may be substan- V tially the same as found in certain types of looms, the gears and pinions constituting a reduction gearing between the warp beam and the regulator therefor to be described. Except for the mounting of the whip roll the parts are substantially of the usual form. In carrying my present invention into efiect I provide each bracket II with a stand 30 and pivot to said stands right and left hand levers 3| and 32, respectively, movable about axes 33 supported by the stands. A rod 35 is pivoted at 36 to the lever 32 and is attached by means of an adjustable rod head 31 to pivot stud 38 carried by lever 3|. The relative angular relation of the levers 3| and 32 can therefore be regulated and maintained, the levers moving in unison because of the rod 35.

Each of the levers 3| and 32 is provided with a pressure arm 40 which bears against a corresponding whip roll support 4| pivoted as at 42 Ito the bracket I Each support 4| has a foot 43 to engage a portion of the associated bracket H to limit rearward motion of the support, or motion to the left as viewed in Fig. 2. Each supjport is provided with a pocket 44 to receive a gudgeon 45 of the whip roll l6. By means of the supports 4| the whip roll is mounted for movement toward and from the front of the loom, the

front of the 100m as viewed in Fig. 3 being at the right. The arms 40 normally exert a rearward pressure on the supports tending to hold the whip roll in the rear or full line position shown in Fig. 2.

The rod head 31 has pivoted thereto as at a link 5| extending to the right as viewed in Fig. 1 and having pivotal connection as at 52 with a regulating lever 53 pivoted at 54 to .an arm 55 secured to the adjacent bracket II. There will ordinarily be but one regulator lever forboth levers 3| and 32. A weight 56 is supported adjustably along the length of notched arm 51 of the lever 53 for the purpose of varying the pressure exerted by the lever arms 40 on the Whip roll supports 4|. 7

The regulator lever 53 has an arm 60 connected at 6| to a rod head 62 ,of a depending rod 63, the lower end of which is pivoted as at 64 to a control lever 65. The rod head permits adjustment of the distance between axes BI and 64. The control lever is pivoted as at 66 to the housing l8 and has an upwardly facing arcuate surface 68 for engagement with a pendulum 69 secured to the bottom of a rod 10 held in longitudinally adjusted position by a set screw H in a bearing 12. The bearing has integral therewith right and left escapement arms 13 and 14, respectively, having shoes 15 and 16, respectively, The bearing rocks on an eccentric stud TI the shank 1B of which passes through the housing and is held in adjusted angular position by a nut 19.

The shoes are adapted for alternate cooperation with a toothed wheel 88 rigid with respect to pinion 28 and shaft 29, so that the pinion 2B and the wheel 80 rotate together with the stub shaft 29. The latter may have a bearing 8! in the cover plate 82 of the housing 18 and a hand wheel 83 on the shaft 29 permits the latter to be turned by the weaver. Bolts 83 may hold the cover in place on the housing and thereby fix the position of the bearing 8!. The teeth of the wheel 80 and the shoes are so related that the wheel can exert a lifting force on either of the shoes 15 or '16, one shoe only at a time having a working relation with the wheel 83.

In operation, theweight 56 will tend to turn regulator lever 53 in a clockwise direction about its pivot 54 as viewed in Fig. 3 and cause the rod 35 and link to be in their right hand position. The weight is therefore effective to position the arms 40 against the supports 4| and 35 hold the whip roll IE to the rear, or in the full line position shown in Fig. 2, with the stop foot 43 against the bracket ll. With the whip roll rearmost the rod 63 is in its highest position and control lever 65 will be up with the arcuate surface 68 pressing against the similarly formed arcuate surface 90 on the bottom of the pendulum 69. In this position of lever 65 the'arcuate surface" 68 is substantially concentric with stud 11.

The pendulum under these conditions will be to the right or full linep'osition of Fig. 2 and shoe 76 will rest on tooth 9| of the wheel 80 in the path of advancing tooth 92. At the same time shoe [5 will be elevated'to clear the teeth of wheel 80 but placed for movement toward tooth 93. Under these conditions the shoe l6 prevents rotation of wheelilii because control lever 65 is in holding relation with the pendulum 96. The warp beam is therefore temporarily locked against advance movement in a right hand direction as viewed in Fig. 2.

As weaving continues the whip roll will move forwardly to the dotted position of Fig. 2 and the supports 4| will rock the levers 3| and 32 in a counter-clockwise direction about their axes 33, resulting in a left hand movement of rod 35 and link 5|. There is a corresponding upmovement of the weight 56 and down movement of rod 63, the latter moving the arcuate surface 68 of the lever 65 away from the pendulum and freeing the latter so that it can movein response to forces exerted by the wheel 80. Because of the tension on the warp the beam will thereupon start to move in an advancing direction and tooth 92 will be forced against the shoe 16, moving the latter and therefore the pendulum to the dotted line position of Fig. 2. As shoe vl6 leaves the wheel 80 the other shoe [5 will move in front of tooth 93. If the resultant'advance motion of the warp slackens the pressure on the whip roll so that the latter moves back to its rearmost position lever 65 will move up against the pendulum and hold the latter in the dotted position of Fig. 2.

At the next operation of the motion the whip roll will again move forwardly to depress lever 65 a second time, after which tooth 93, being now in'the dotted position shown in Fig. 2, will lift the shoe 15 from the dotted tooth full line position shown in Fig. 2 and cause the pendulum to move back to the full line position. The operation just described assumes that the rate of feed of the warp is such that a single motion 'of the pendulum will suffice to pay off enough yarn to return the whip roll to its rearmost position.

If the rate of feed is' faster than that just described, however, the outward and return swing of the pendulum will occur consecutively and be accompanied by a single motion of the whip roll back to its rearmost position. The escapement mechanism is such that any desired number of swinging motions of the pendulum can occur for each return motion of the whip roll to normal position.

Adjustment of the shoes 15 and 16 relatively to the wheel 80 can be gotten by changing the angular setting of the stud T! by a loosening and subsequent tightening of nut 19. This also effects a slight adjustment between the swing of the pendulum and the arcuate surface 68.

From the foregoing it will be seen that the weight tends normally to lock the pendulum and therefore prevent turning of the tooth wheel 80 and feeding of the warp, but forward movement of the whip roll causes the control lever to move away from the pendulum, whereupon the wheel 80 is free to rotate to permit paying-off of the warp until backward movement of the whip roll induced by the weight again lifts the control lever 65 into locking relationship with the pendulum. The vertical adjustment of rod permits proper location of the pendulum so that the latter can be locked by the lever 65 when the foot 43 is against its stop and the whip roll is rearmost. It will further be seen that the releasing of the lock for the let-off is effected by forward movement of the whip roll, which in turn is caused by tightening the warp simultaneously with raising of the weight, and that the latter without substantial variation is effective throughout the unwinding of the warp to maintain uniform feeding. The rod 35 together with its connections through levers 3! and 32 and the supports for the whip roll cause a parallel for- .ward motion of the whiproll the effect of which is to insure uniform tensioning of the warp throughout the length of the beam.

While I have described hereinbefore the action of the weight 69 and the lever 65 with reference to its extreme positions, yet I find in actual practice that the weight assumes a large variety of positions of rest aleng the arcuate surface 68 suggesting that the left-off action does not require a complete swing of the weight. The surface 68 acts as a brake to hold the weight in its various positions. Because of the relation between the wheel 80 and the escapement a comparatively light braking pressure between the lever 65 and weight 69 will suflice to hold the warp against advance feeding until the whip roll has advancedrsuniciently to cause a changed relation between the lever 65 and the weight. Because of the considerations just set forth the weight may in effect be considered as part of a braking device for the escapement and so far as this feature of the invention is concerned the mass of the weight is of no particular consequence.

Having thus described my invention it will be seen that changes and modifications may be made therein by those skilled in the art without departing from thespirit and scope of the invention and I do not wish to be limited to the details herein disclosed, but what I claim is:

1. In a let-off for a loom, a rotatable warp beam tending to turn forwardly under tension of the warp, an escapement wheel connected to and turning with the beam, an escapement device oscillatable by a force derived from the escapement wheel and capable of preventing rotation of the wheel when oscillation of said device is prevented, brake means to prevent oscillation of the escapement device when the warp tension is normal, means actuated by increased tension of the warp to move the braking means out of braking relation with respect to the escapement device, whereupon tension of the warp turns the beam and wheel, and means to return the braking means to braking relation with respect to the escapement device to prevent further rotation of the escapement wheel and beam when the warp tension returns to normal.

2. In a 1et-off for a loom, a warp beam tending to turn under action of the tension of the warp,

an escapement wheel turning with the beam, an escapement device in engagement with the escapement wheel and tending to oscillate by a force derived from the wheel and capable when held against oscillation to prevent turning of the wheel and beam, preventing means operative when the warp tension is normal to hold the escapement device against oscillation, releasing means brought into action by an increased tension in the warp to move the preventing means out of holding relation with respect to the device, whereupon the latter oscillates and the wheel and beam turn, and mechanism thereafter effective' to restore the preventing means to holding relation with respect to the escapement device when the warp tension returns to normal due to turning of the beam.

3. In a let-off for a loom, a warp beam tending to turn under action of the tension of the warp, an escapement wheel turning with the beam, an escapement device in engagement with the escapement wheel and tending to oscillate by a force derived from the wheel and capable of preventing turning of the wheel and beam when held against oscillation, a brake lever to prevent oscillation of the escapement device and cause the latter to prevent turning of the wheel, an element movable away from normal position when the warp tension is increased, connections between the element and the lever to move the latter out of braking relation with respect to the escapement device when said element moves away from normal position due to increased warp tension, whereupon the wheel causes the escapement device to oscillate and turn to permit turning of the beam under action of the warp, and means efiective after the warp tension is reduced by turning the beam to return said element to normal position and return the brake lever to holding relation with respect to the escapement device.

4. In a let-ofi for a loom, a warp beam tending to turn under action of the tension of the warp, an escapement wheel turning with the beam, an escapement device in engagement with the escapement wheel and tending to oscillate by a force derived from the wheel and capable when held against oscillation to prevent turning of the wheel, brake means for the escapement device normally effective to prevent oscillation of the latter and cause the same to hold the wheel and beam against turning, a whip roll movable forwardly from a normal position by an increase in warp tension, connections between the whip roll and the brake means to move the latter to a position to release the escapement device when the whip roll moves forwardly due to increased warp tension, whereupon the wheel turns to escillate the escapement device and permit turning of the warp beam under tension of the warp, and yielding means effective when the warp tension is reduced by turning of the loom to move the whip roll rearwardly to normal position and move the brake means into holding relation with respect to the escapement device.

5. In a let-off for a loom, a warp beam tending to turn underaction of the tension of the warp, an escapement wheel turning with the beam, an escapement device in engagement with the escapement wheel and tending to oscillate by a force derived from the wheel and capable of preventing turning of the wheel and beam when oscillation thereof is prevented, a whip roll movable forwardly from normal position by increased wfarp tension, a weight to move the whip roll rearwardly, brake means for the escapement device normally preventing oscillation of the latter and causing the same to prevent turning of the escapement wheel, connections between the whip roll and the brake means to move the latter out of braking relation with respect to the escapement device when the whip roll moves forwardly, the weight falling when the warp tension is reduced byturning the beam to return the whip roll to normal rearward position and restore the brake means to holding relation with respect to the escapement device and prevent further oscillation of the latter.

6. In a let-off 'for a loom, a rotatable warp beam, an escapement wheel, means to gear the wheel to the beam to cause the wheel and beam to turn together, an escapement device to engage the wheel and capable when locked of preventing movement of the latter, holding means normally effective to lock the escapement device in position to prevent movement of the wheel, a whip roll movable forwardly in response to pressure of the warp of the beam, and connections between the whip roll and the holding means to disconnect the latter from the escapement device when the whip roll moves forwardly, the whip roll and beam being thereby rendered free to rotate under action of the warp thread.

7. In a let-off for a loom, a rotatable warp beam, an escapement wheel, means to cause the latter to rotate with the beam, a pivoted escapement device for the wheel capable when locked of preventing rotation of the latter, a control lever for the escapement device having an arcuate surface, means moving with the escapement device to engage the arcuate surface to lock the escapement device in position to prevent rotation of the escapement wheel, a whip roll movable in response to pressure of the warp thread of the beam, and connections between the whip roll and the control lever to move the latter to a position to release the escapement device, whereupon pressure of the warp threads turn the Warp beam and escapement wheel.

8. In a let-off for a loom, a rotatable warp beam, an escapement wheel connected to and turning with the beam, an escapement device for the escapement wheel, preventing means normally holding the escapement device in position to restrain rotation of the escapement wheel, a whip roll movable forwardly by pressure of the warp thread of the beam, weight means to move the whip roll rearwardly, and connections between the whip roll, weight means and the preventing means of the escapement device effective when the whip roll is moved forwardly by pressure of the warp to disconnect the preventing means from the escapement devices and lift the weight means, thereby releasing the escapement wheel to render the warp thread eifective to turn the beam and wheel, the weight means to be effective to move the whip roll rearwardly and restore the preventing means to normal holding relation with respect to the escapementdevice after movement of the escapement wheel.

9. In a let-ofi for a loom, a rotatable warp beam, an escapement wheel connected to and rotating with the beam, an escapement device for the escapement wheel capable of preventing rotation of the latter when said device is held against movement and the wheel being free to turn when the device is free, holding means for the escapement device to hold the latter in a position to prevent turning of the escapement wheel, a whip roll movable forwardly in response to pressure of the warp thread of the beam, two levers, one for each end of the whip roll, to exert backward pressure on the whip roll, said levers movable forwardly with the whip roll, connections between said levers and the holding means to move the latter out of holding relation with respect to the escapement device tofree the latter when the whip roll moves forwardly, the wheel being thereupon free to turn, and force exerting means attached to said connections, to mo ve the levers in a direction tomove the whip roll rearwardly and efiective to movethe holding means into holding relation relatively to the escapement device and render the latter eiTective to prevent turning of the wheel and beam.

10. In a let-off for loom, a rotatable warp beam, an escapement wheel connected to and rotating with the beam and having teeth, an oscillatable escapement device having two spaced shoes which alternately have holding relation with respect to.

the wheel, either shoe when engaging a tooth of the wheel preventing rotation of the latter when oscillation of the device is prevented, the wheel tending to turn under the force of the warp thread when one shoe moves away from the wheel and the other shoe moves toward said wheel, holding means for the escapement device to prevent oscillation ofthe device and retain the latter with either shoe in contact with the wheel, a whip roll movable forwardly under pressure of the warp of the beam, and connections between the whip roll and theholding means to transmit a force from the whip roll to said holding means and move the latter out of holding relation with respect to the escapement device when the whip roll moves forwardly to release said escapement device, whereupon the wheel turns to oscillate the escapement devices to permit turning of the warp beam and move one shoe away from and the other shoe toward said wheel.

l OSCAR V. PAYNE. 

